Inhibition body tremors

Dopamine s role in the coordination of movement can be partially understood by examining Parkinson s disease. This illness is associated with low levels of dopamine in the brain and is characterized by spastic motion of the eyelids as well as rhythmic tremors of the hands and other parts of the body. One method of treating Parkinson s disease is to increase the concentration of dopamine in the brain. This is most effectively accomplished by administering the precursor of dopamine, L-dopa. In order to prevent concentrations of norepinephrine from increasing as well, L-dopa is given in conjunction with a drug that inhibits norepinephrine synthesis. 

Acetylcholine is broken down by the acetylcholinesterase enzyme to choline and acetate. The time required for hydrolysis of acetylcholine is less than a millisecond. If the enzyme is depleted or inhibited, then excessive acetylcholine accumulation in the body can cause toxicity. Symptoms are salivation, lacrimation, urination, diarrhea, muscle tremor, and fasciculation. 

Researchers have discovered that there are two types of monoamine oxidase enzyme MAO-A and MAO-B, each located in different regions of the body. Older MAOIs, such as Nardil, inhibit both versions of monoamine oxidase, resulting in increased serotonin and norepinephrine inside the cell (and also leakage into the synapse, thus activating receptors). Increases in serotonin and noreinephrine receptor activation can lead to several over-stimulating side effects. These central nervous system effects include tremors, insomnia, agitation, and occasionally, precipitation of a mania in patients with bipolar depression. 

---